Patch 0072-Further-Seed-Customisation provides customizable seeds for different world features.

Unfortunately, there isn't one for End Cities.

Given that there are newer features in that patch (i.e. `shipwreck`, `outpost`), I assume there's a reason for that, but I was unable to find a ticket.

I'm considering PRing it myself, but first need to learn how Spigot patching works and how do add missing files - so in the meantime creating this feature request.